View Single Post
  #3  
Old 08-19-2009, 12:50 PM
marty marty is offline
Senior Member
 
Join Date: Jun 2007
Posts: 118
Talking 1 K

Hi;
I should have restated what I last said in my last post, When trying an unknown pin , then go thru a resistor, to protect the circuit and the power supply, such as connecting a line that goes to ground to a +5 , by going thru a resistor you find out what is happening without shorting to something else, without a limiting resistor....
On pin 11 of the 74L30 it is an input and with no connection it would float high , so connecting it to +5 would eliminate the possibility of it going low at any time... You could connect it to pin 12 next to it which is connected to pin 14 on the board... and this would eliminate any interference of any kind to the Ic...
THANK YOU Marty
Reply With Quote